The proposed research will increase our understanding of age differences in basic cognitive processes that are fundamental to language and memory. The experiments test two accounts of cognitive aging: the Transmission Deficit hypothesis and the Inhibitory Deficit hypothesis. We test contrasting predictions of these hypotheses for age deficits in word retrieval and memory performance. The long-term goal is to contribute to the development of theories of aging that apply to a broad spectrum of cognitive performance, and that are sufficiently well specified to make testable predictions for cognitive tasks. A related goal is to increase our understanding of the mechanisms involved in certain asymmetries in cognitive aging, for example, the robustness of semantic retrieval processes and the decline in phonological retrieval processes. The research is concerned with cognitive problems that vex older adults in everyday life, for example, tip of the tongue states, and it identifies conditions that either exacerbate or reduce these problems. Three sets of experiments are proposed. Experiments 1-4 investigate the role of phonological processes in older adults' impairment in retrieving proper names of well known people. We also examine whether phonological inputs speed resolution of tip of the tongue states. This study will identify everyday activities that facilitate resolution of TOTS, a topic of keen interest to older adults. Experiments 5-7 uses a "competitor priming" paradigm to examine age differences in resolving competition among words during word retrieval in an object naming task. A finding that older adults' performance is more disrupted by competition will identify an important source of the increase in speech disfluencies in old age. Experiments 8-10 evaluate the hypothesis that age-related increases in interference on the Stroop color naming task are caused by inhibitory deficits in older adults. We measure inhibition by examining suppression of the baseword both during color naming and in a subsequent implicit memory task.